| /* |
| * Copyright (c) 2011, Rickard Öberg. All Rights Reserved. |
| * Copyright (c) 2012, Paul Merlin. All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| package org.apache.zest.library.sql.common; |
| |
| import java.sql.Connection; |
| import java.sql.PreparedStatement; |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import javax.sql.DataSource; |
| import org.apache.zest.functional.Visitor; |
| import org.apache.zest.io.Input; |
| import org.apache.zest.io.Output; |
| import org.apache.zest.io.Receiver; |
| import org.apache.zest.io.Sender; |
| |
| /** |
| * Utility methods for performing SQL calls wrapping a given DataSource. |
| */ |
| public class Databases |
| { |
| |
| DataSource source; |
| |
| /** |
| * Create a new Databases wrapper for a given DataSource. |
| */ |
| public Databases( DataSource source ) |
| { |
| this.source = source; |
| } |
| |
| /** |
| * Perform SQL update statement. |
| */ |
| public int update( String sql ) |
| throws SQLException |
| { |
| Connection connection = null; |
| PreparedStatement stmt = null; |
| try { |
| connection = source.getConnection(); |
| stmt = connection.prepareStatement( sql ); |
| return stmt.executeUpdate(); |
| } finally { |
| SQLUtil.closeQuietly( stmt ); |
| SQLUtil.closeQuietly( connection ); |
| } |
| } |
| |
| /** |
| * Perform SQL update statement. |
| * |
| * If the SQL string contains ? placeholders, use the StatementVisitor to |
| * update the PreparedStatement with actual values. |
| */ |
| public int update( String sql, StatementVisitor visitor ) |
| throws SQLException |
| { |
| Connection connection = null; |
| PreparedStatement stmt = null; |
| try { |
| connection = source.getConnection(); |
| stmt = connection.prepareStatement( sql ); |
| visitor.visit( stmt ); |
| return stmt.executeUpdate(); |
| } finally { |
| SQLUtil.closeQuietly( stmt ); |
| SQLUtil.closeQuietly( connection ); |
| } |
| } |
| |
| /** |
| * Perform SQL query and let visitor handle results. |
| */ |
| public void query( String sql, ResultSetVisitor visitor ) |
| throws SQLException |
| { |
| query( sql, null, visitor ); |
| } |
| |
| /** |
| * Perform SQL query and let visitor handle results. |
| * |
| * If the SQL string contains ? placeholders, use the StatementVisitor to |
| * update the PreparedStatement with actual values. |
| */ |
| public void query( String sql, StatementVisitor statement, ResultSetVisitor resultsetVisitor ) |
| throws SQLException |
| { |
| Connection connection = null; |
| PreparedStatement stmt = null; |
| ResultSet resultSet = null; |
| try { |
| connection = source.getConnection(); |
| stmt = connection.prepareStatement( sql ); |
| if ( statement != null ) { |
| statement.visit( stmt ); |
| } |
| resultSet = stmt.executeQuery(); |
| while ( resultSet.next() ) { |
| if ( !resultsetVisitor.visit( resultSet ) ) { |
| return; |
| } |
| } |
| resultSet.close(); |
| } finally { |
| SQLUtil.closeQuietly( resultSet ); |
| SQLUtil.closeQuietly( stmt ); |
| SQLUtil.closeQuietly( connection ); |
| } |
| } |
| |
| /** |
| * Perform SQL query and provide results as an Input. |
| * |
| * This makes it possible to combine SQL data with the I/O API. |
| */ |
| public Input<ResultSet, SQLException> query( final String sql ) |
| { |
| return new Input<ResultSet, SQLException>() |
| { |
| |
| @Override |
| public <ReceiverThrowableType extends Throwable> void transferTo( Output<? super ResultSet, ReceiverThrowableType> output ) |
| throws SQLException, ReceiverThrowableType |
| { |
| output.receiveFrom( new Sender<ResultSet, SQLException>() |
| { |
| |
| @Override |
| public <ReceiverThrowableType extends Throwable> void sendTo( final Receiver<? super ResultSet, ReceiverThrowableType> receiver ) |
| throws ReceiverThrowableType, SQLException |
| { |
| query( sql, new ResultSetVisitor() |
| { |
| |
| @Override |
| public boolean visit( ResultSet visited ) |
| throws SQLException |
| { |
| try { |
| receiver.receive( visited ); |
| } catch ( Throwable receiverThrowableType ) { |
| throw new SQLException( receiverThrowableType ); |
| } |
| |
| return true; |
| } |
| |
| } ); |
| } |
| |
| } ); |
| } |
| |
| }; |
| } |
| |
| /** |
| * Perform SQL query and provide results as an Input. |
| * |
| * This makes it possible to combine SQL data with the I/O API. If the SQL |
| * string contains ? placeholders, use the StatementVisitor to update the |
| * PreparedStatement with actual values. |
| */ |
| public Input<ResultSet, SQLException> query( final String sql, final StatementVisitor visitor ) |
| { |
| return new Input<ResultSet, SQLException>() |
| { |
| |
| @Override |
| public <ReceiverThrowableType extends Throwable> void transferTo( Output<? super ResultSet, ReceiverThrowableType> output ) |
| throws SQLException, ReceiverThrowableType |
| { |
| output.receiveFrom( new Sender<ResultSet, SQLException>() |
| { |
| |
| @Override |
| public <ReceiverThrowableType extends Throwable> void sendTo( final Receiver<? super ResultSet, ReceiverThrowableType> receiver ) |
| throws ReceiverThrowableType, SQLException |
| { |
| query( sql, visitor, new ResultSetVisitor() |
| { |
| |
| @Override |
| public boolean visit( ResultSet visited ) |
| throws SQLException |
| { |
| try { |
| receiver.receive( visited ); |
| } catch ( Throwable receiverThrowableType ) { |
| throw new SQLException( receiverThrowableType ); |
| } |
| |
| return true; |
| } |
| |
| } ); |
| } |
| |
| } ); |
| } |
| |
| }; |
| } |
| |
| /** |
| * Visitor for PreparedStatements. |
| * |
| * These are created when the SQL statements contain ? placeholders. |
| */ |
| public interface StatementVisitor |
| { |
| |
| void visit( PreparedStatement preparedStatement ) |
| throws SQLException; |
| |
| } |
| |
| /** |
| * Visitor for the ResultSet. |
| * |
| * Only access data from the given ResultSet, as the iteration will be done |
| * by this API. |
| */ |
| public interface ResultSetVisitor |
| extends Visitor<ResultSet, SQLException> |
| { |
| } |
| |
| } |